In recent years surgery has markedly advanced through the performance of laparoscopic and endoscopic surgical procedures such as cholecystectomies, gastrostomies, appendectomies, and hernia repair. Laparoscopic surgery, which can also be referred to as minimally invasive surgery, is a surgical technique that includes operations performed through small incisions in the body of a patient. There can be a number of advantages to the patient with laparoscopic surgery compared to open procedures where larger incisions are made. For example, pain and hemorrhaging can be reduced due to the smaller incisions and recovery times can be shorter.
In a conventional laparoscopic procedure, a distal end of a laparoscopic or electrosurgical device can be passed through a small incision in the skin of a patient. The distal end of the laparoscopic device is then positioned at or adjacent a surgical site. One or more surgical procedures are then performed at the surgical site, which can include cutting and/or sealing tissue. The distal end of the laparoscopic device can be removed from the patient after the completion of the surgical procedure.
Many laparoscopic devices include a pair of jaws for grasping or otherwise effecting tissue. Movement of the jaws between open and closed positions is controlled by an actuation assembly, which transmits a force from the handle to the opposed jaws. The force required to close the jaws can increase with thicker or stiffer tissue, and/or in applications where the jaws are applying a closure mechanism, such as a clip or staple, to the tissue. The actuation assembly can require manual application of force by a user to actuate the actuation assembly, and this manual force can become difficult to apply when the force required to actuate the actuation assembly becomes great, such as in the case of thicker or stiffer tissue. In the event that excessive forces are transmitted by the actuation assembly, undesired damage to the tissue can result. In addition, since the actuation assembly requires precise timing and coordinated movement between numerous components, excessive forces applied to close the jaws can result in damage to the components of the actuation assembly.
Accordingly, there remains a need for improved devices and methods for clamping and cutting tissue.